The painting pivots around the scene of the mystical marriage of St. Catherine of Alexandria, while around her a sacra conversazione is held. Their participants are, on the right, St. Paul and St. Sebastian and, on the left, St. Peter and St. John the Baptist. The scene setting is rather conventional, though Lippi's usual taste for bizarre decorations can be seen in details such as the harpy sculpted on a corner of Virgin's throne or the fragment of the wheel on which St. Catherine would have been tortured. Also the architecture in the background is rather classical.